1. Field of the Invention
The present invention relates to a pressure modulator device for anti-locking brake systems in automotive vehicles.
2. Description of Related Art
In automotive vehicles provided with an antilocking braking system, when braking of a braked wheel exceeds a given deceleration threshold, for instance 12 m/s.sup.2, the anti-locking device generates an electric signal to reduce the braking pressure until a lower second deceleration threshold, for instance 10 m/s.sup.2, is passed. Thereafter, the anti-locking device generates an electric signal to increase the braking pressure and deceleration increases again up to the first deceleration threshold.
This increasing and decreasing of the braking pressure may be effected by means of a pressure modulator device as disclosed in commonly assigned U.S. patent application Ser. No. 899,212 filed Aug. 21, 1986 now U.S. Pat. No. 4,691,813 issued August 1987, the disclosures of which are incorporated herein by reference.
Related developments are disclosed in commonly assigned U.S. Pat. No. 4,511,971; U.S. patent applications Ser. No. 899,201, allowed and Ser. No. 899,208 now U.S. Pat. No. 4,717,211 issued Jan. 5, 1988, both filed Aug. 21, 1986; and U.S. patent application Ser. No. 22,797 filed Mar. 6, 1987, of even date herewith. These disclosures are also incorporated herein by reference.